Throttle



N. T. M KEE Dec. 12, 1933.

THROTTLE Filed Dec.

5 Shets-Sheet l INVENTOR ATTORNEY Dec. 12, 1933. N. T. MCKEE 1,938,710

N 7,- Mi KEE INVENTOR @KZGLQ ATTORNEY Dec. 12, 1933.

N. T. M KEE 21, 1929 5 Sheets-Sheet 3 IIIVIIII INVENTOR ATTORNEY N. T. McKEE Dec. 12, 1933.

THROTTLE Filed Dgc 21, 1929 I 5 Sheets-Sheet 4 A4 7': M5 was INVENTOR BY if.

ATTORNEY Patented Dec. 12, 1933 -UNITED STATES PATENT OFFICE THROTTLE Application December 21, 1929 Serial No. 415,773 v 14 Claims.

My invention relates to hand-operated valves and operating mechanisms therefor.

For a long period, hand-operated throttles for locomotives were exclusively of the single valve balanced type. A multiple throttle valve design has been proposed, however, in which the individual valves are opened one after the other and in which thevalves are unbalanced. Such designs require that the individual valves be small enough to permit them to be opened without undue exertion by the engineer. At the pressures proposed for some recent locomotives, this requires that an uncommercial'number of valves must be employed in each throttle structure.

An object of my invention is to provide a novel operating mechanism adapted for use with hand-operated throttles and capable of applying very high opening force to the throttle valves so that comparatively large unbalanced valves may be employed.

Another object of the present invention is to provide a novel hand-operated valve and operating mechanism therefor adapted for commercial use in a multiple throttle valve of the general type .disclosed in Patent #1,662,955 when made with unbalanced valves. 7

The novel features of my invention will be pointed out in the appended claims. The invention itself, however, together with further objects and advantages, will best be understood from a detailed description of two illustrative forms of throttle valve and an operating apparatus therefor embodying my invention, and such a description will now be given in connection withthe annexed drawings, in which Fig. 1 is a transverse sectional view on a vertical plane through the upper portion of the front end of a locomotive equipped with my invention, parts being broken away for purposes of illustration; Fig. 2 is a section on line 2-2 of Fig. 1;' Fig. 3 is a plan of the portion of the locomotive shown in Figs. 1 and 2, parts being broken away and parts being shown in section for purposes of illustration; Fig. 4 is a fragmentary view of a portion of Fig. 2 on an enlarged scale; Fig. 5 is a fragmentary view illustrating a modified form of throttle valve substituted in the portion of Fig. 4 above the line AA; Fig. 6 is a fragmentary sectional elevation on line 6--6 of Fig. 4; and Fig. 7 is a fragmentary elevation of the lower portionofthe operating gear shown in Fig. 4 taken from the right of Fig. 4.

Referring to the drawings, 1 designates the front flue sheet of a locomotive boiler. separating the steam and water space 2 from the smoke box 3. Steam for the cylinders is taken from a convenient point in the steam space by dry pipe 4 connecting with the pipe 5 from which steam is delivered to branch steam pipes 66 leading to the individual cylinders through a throttle valve structure indicated generally by 7. It has become common practice to employ superheated steam in locomotive cylinders and the arrangement illustrated comprises means for superheating steam interposed between the pipe 5 and the throttle 7 and having a superheater header 8 having hollow fingers 9, 9 (Fig. 3) from which wet steam is taken by connecting tubes 10, 10 delivering the steam into superheater elements 11, 11 which extend into enlarged smoke tubes 12, 12 of the boiler. superheated steam is delivered from the elements 10 to the fingers 14, 14 ofheader 8 interleaved with fingers 9 and which receive the superheated steam from elements 11 through connections 15, 15 and deliver it to the risers 13. The risers 13 communicate with steam space 16 in the throttle structure '7. Within the structure 7 is a wall 17 separating the space 16 for the superheated live steam from the space 18 which connects to the branch pipes 6. The wall 17 is provided witha plurality of ports 19 each of which is controlled by a throttle valve 20. It will be understood that the structures heretofore described comprise only known features. V

In accordance with my invention, valve 20 has a central aperture 21 and a hollow stem 22 whose hollow serves as an extension of the aperture 21. Stem 22 extends upwardly from the valve proper into a recess 24 within acap 26 which closes an aperture 28 in the wall of the structure '7. Stem 22 is guided in the cap 26 as indicated at 30. V

A plug 32 is threaded into the upper end of the stem for purposes which will presently appear. The cap 26 is provided with inclined apertures 34, 34 extending from the steam space 16 through the vertical side wall of chamber 24. To prevent trapping so much steam above the stem 22 and plug 32 on the opening movement of the valve as would cause an objectionable increase in resistance of the valve when the stem has moved past the upper ends of passages 34, said vertical side wall is offset somewhat at 35 from the guide surface 30. However, the amount of offset at 35 can be made such that any tendency of the valve to fly open suddenly after once leaving the seat may be counteracted by a partial trapping of steam above the stem 22 and plug 32.

The plug 32, in addition to preventing leakage through the valve, forms part of the means for operating the valve. Such means includes a valve rod 36 having a ball 38 fixed to its upper end, said ball engaging on its lower face with a split ring 40 seated in a rabbet 42 in the inner face of the stem 22 and which prevents ball 36 from passing down through opening 21. The lower end of plug 32 is hollowed out at 44 to form a bearing for the upper surface of ball 38. As the plug and split ring are held in the stem 22, the stem 22 not only acts as part of the means to guide valve 20, but also as part of the means to attach the rod 36 to valve 20. It will be seen also that by taking off cap 26, plug 32 may be removed from stem 22. The rod 36 may then be raised clear of stem 22 by the rod operating mechanism such as that described below so that ring 40 can be removed from the ball 38 to disconnect the valve and rod and permit removal of the valve upwardly through opening 28 by passing ball 38 through the valve.

The valve rod 36 extends downward through aperture 21 and has at its lower end an offset arm 46 fixed thereto the outer end of which is pivoted on pin 48 fixed to a lever 50 keyed at 51 to a shaft 52. Shaft 52 is mounted to permit it to oscillate and it may be connected for this purpose to the usual manually-operated throttle lever by any suitable means such for instance as that shown in Patent 1,662,955 and indicated at 53 (Figs. 1 and 3). The valve 20 and the operating gear therefor is shown in Fig. 2 in the closed position and, in order that the valve may be opened upon turning the shaft 52 in the proper direction, I prefer to provide for operating rod 36 a fixed cam 54 shown as formed on a detachable cap 56 closing an aperture 58 in the structure 7, the cam 54 being of such form and so placed that during the initial opening movement of the valve the rate of movement of the valve relative to the angular movement of the actuating rod 36 is very small with a resultant great multiplication of the force exerted by the engineer, while such relative rate increases thereafter. In the arrangement shown, the cam 54 is concave toward the valve 20 and a roller 56 is provided which is mounted on the lower end of valve rod 36 and rests on the cam 54. It will be seen that as the shaft 52 is turned in the clockwise direction as viewed in Fig. 4, the valve rod will be swung to the left and the roller 56 moved up along the cam surface 54 to a point closer to the valve seat 21, thereby forcing open valve 20. The operative surface of the cam is such that, assuming the valve to be horizontal, said surface is arranged with a portion 5411 which is inclined only slightly to the horizontal and with which the roller 56 is in contact when the valve is closed, the cam, however, curving upward more rapidly after passing from the nearly horizontal part 54a to accelerate the rate of opening of valve 20 for a given rate of movement of shaft 52. The relative positions of the parts during the opening movement of the valve are indicated by two curves F and G, showing respectively the paths of the centers of the pin 48 and the roller 56 The parts are shown in the position occupied while valve 20 is closed, the positions of the centers of parts 48 and 56 under this condition being indicated on the two curves by character 0, and a series of simultaneous positions occupied successively by the two centers during the opening movement of the valve are indicated on the two curves F and G by characters 101, 102, 103, 104 and 105.

To exert the maximum force on the valve at the beginning of its opening movement, it is convenient to so arrange the parts that the valve rod 36 shall lie on one side of the axis of the valve 20 when the valve is closed and shall swing to the other side of such axis soon after the valve opens.

I A feature of the invention relates to a convenient arrangement for attaching the roller 56 to the parts 36 and 46. It will be seen that the valve rod 36 and arm 46 are integral, extending approximately at a right angle to each other, so that the two form a bell crank. At the apex of theangle, the bell crank is bifurcated to form spaced parallel plates 60, 60, between which roller 56 is received and held in place by a pin 62 passing through the plates 60. Roller 56 is preferably provided with an anti-friction bearing, such bearing being illustrated as composed of rollers 64 between the pin 62 and the inner face of the roller 56.

My improved operating mechanism is not limited to unbalanced valves and affords opportunity to employ partially balanced valves having a considerable degree of unbalancing to ensure tight closing of the valve. Such a valve is shown in Fig. 5 and comprises a main valve 20:1 105 having a central aperture 21a and a hollow stem 22a. whose opening serves as an upward continuation of aperture 21a. Stem 22a is guided and arranged to reciprocate in a cap 2611 fixed to the casting 7a. The stem 22a is sufficiently large to 110 receive a hollow pilot valve '70 and provides a seat 72 for the pilot valve at its lower end. Pilot valve 70 has an aperture '71 which connects with the hollow of stem 22a and through which the valve rod 36 extends. The head 38 of the 115 valve rod 36 is secured to valve 70 by means of a split ring 40a and a plug 42a. The pilot valve '70 is mounted to reciprocate in the stem 22a and has for this purpose a guiding contact with ribs 74 on the inner face of the stem above its seat. 120 When the parts are in the position shown, the main valve 200. is held against its seat 21a by pressure against its upper face and by pressure exerted against the upper end of the stem 22a and against the top of the valve '70 and plug 42a 1'25 by steam which has leaked from the steam space 18a into the chamber 24a along the surface between the stem 22a and cap 26a, the pressure on valve '70 and plug 42a being transmitted to valve 20a through seat '72. Such pressure, together with the weight of the valve rod, holds the pilot valve 70 firmly against its seat 72 so that there is no leakage through the central aperture 210, of the valve from the chamber 24a into the chamber 18a. When, however, it is intended to open valve 2011, the valve rod 36 is operated by mechanism such as that described in connection with valve 20 of Fig. 2 to lift the pilot valve '70, thereby equalizing the pressures in chambers 24a and 18a and wholly or partially balancing the valve 20a depending upon the relative proportions of the body of the valve and the stem 22a. Further upward movement of the valve 70 brings it into contact with a cross pin '76 fixed in the upper portion of the stern 22a, and still further movement of the pilot valve therefore opens the main valve 20a. The remainder of the operating mechanism for valve 20a being the same as that for valve 20 is not further described.

It will be obvious that the path of the pin 48 151- is such that a valve connected thereto through a rod such as rod 36 would have an opening movement having very low speed and highpressure at the time the valve is first started from its seat followed by a relatively rapid acceleration away from the seat with further movement of pin 48, assuming a uniform rate of speed of the pin throughout. Therefore the cam 54 may be omitted while retaining the same general method of operation as above described. It will be understood however, that it is preferred to use the cam and that when the cam is used, sufficient lost motion is employed in the joints of the apparatus to permit the pressure of the valve rod 36 to rest on the cam rather than on the pin 48. When a number of valves are to be operated from one shaft 52, the individual valves of course are opened and closed serriatim, and it will be understood that for this purpose the cranks 54 for the different valves are set at different angles with respect to the shaft 52 and that more lost motion is employed than if only one valve were to be operated by a given shaft 52.

I claim: a

1. A valve operating mechanism comprising a valve and a guide therefor, a valve rod pivotally and directly connected to said valve and arranged to swing transversely of the line of mo ,tion of the valve, means to swing said rod, and

means cooperating with said rod and arranged to act directly thereon to move said valve relatively slowly during its initial opening movement and relatively quickly after the valve has left its seat.

2. A valve operating mechanism comprising a shaft having a lever thereon, a valve and guide therefor, a valve rod pivotally and directly connected to said valve and to said lever, and arranged to swing transversely of the line of motion of the valve when said shaft is turned, and means for cooperating with said rod and arranged to act directly thereon to apply relatively high opening pressure to the valve as the valve is leaving its seat, and to accelerate the valve movement after the valve has left its seat.

3. A valve operating mechanism comprising a valve and a guide therefor, a valve rod pivotally connected to said valve and arranged, to swing transversely of the line of motion of the valve, means to swing said rod, and means cooperating with said rod to open said valve during its swinging movement and including a fixed cam surface arranged to apply a relatively high opening pressure to start the valve from its seat and thereafter to accelerate the opening movement of the valve for a given angular movement of said rod.

4. Mechanism as set forth in claim 3 and in which a roller is carried on the valve rod to transmit the operating pressure from the fixed cam to the rod.

5. A valve operating mechanism comprising a rotatable shaft having a lever thereon, a valve and a guide therefor, a valve rod and an arm rigid therewith and forming a bell crank pivotally connected to said valve and to said lever and so arranged that the rod swings transversely of the line of motion of the valve when said shaft is turned, a roller fixed to the angle of said crank, and a fixed cam cooperating with said roller to apply a pressure to said rod in the direction to open said valve when said shaft is turned.

6. A mechanism as set forth in claim 3 and in which the fixed cam has 'a' central rib .and

the roller a central depression receiving said:

rib. 8. In a valve operating mechanism comprising a valve and a guide therefor, a valve rod pivotally connected to said valve and arranged to swing transversely of the line of motion of the valve, means to swing said valve rod, and means cooperating with said rod during its swinging movement to open said valve and including a fixed cam intersected by the axis of the valve, the valve rod being arranged to swing from the one side of the axis of the valve to the other during the opening movement of the valve.

9. The combination with a supporting structure having an aperture in its outer wall and having an interior valve seat, of an apertured valve cooperating with said seat and having a hollow stem extending to one side thereof, a cap for the aperture in said structure in which said stem is guided, a valve rod extending through said valve and pivoted in said stem, means normally securing said rod to said stem and adapted to be disassembled when said cap is removed from said structure to permit disconnecting said rod from said stem, and a fixed cam cooperating with the valve rod to lift the valve when the rod is moved relatively to the cam.

10. The combination with a supporting structure having an aperture in its outer wall and having an interior valve seat, of an apertured valve cooperating with said seat and having a hollow stem extending to one side thereof, a cap for the aperture in said structure in which said stem is guided, a valve rod extending through said valve and pivoted in said stem, means normally securing said rod to said stem and adapted to be disassembled when said cap is removed from said structure to permit disconnecting said rod from said stem, a fixed cam cooperating with said rod and arranged to lift the valve when the rod is moved relatively to the cam, and a cap detachably connected to said structure on which said cam is carried.

11. The combination with a supporting structure having an aperture in its outer wall of a valve mounted within said structure, means for operating said valve including a normally fixed cam, and a cap for said aperture on which said cam is mounted.

12. The combination of a casting having an internal web forming two chambers therein, the two outer walls of the casting and said web having a set of aligned apertures therein, a valve for the aperture in said web, a cap for the aper ture in one of said walls having a guide thereon for said valve, and operating means for said valve including a cap'for the aperture in the other of said walls, said last mentioned cap having a cam fixed thereto.

13. A valve operating mechanism comprising a valve and a guide therefor, a valve rod pivotally and directly connected to said valve and arranged to swing transversely of the line of motion of the valve, means to swing said rod, and means cooperating with said rod to move said valve relatively slowly during its initial opening movement and at a relatively higher rate throughout the remainder of the opening movement of the valve.

14. The combination with a chamber having a plurality of walls and an aperture in one of said walls, of an oscillatory shaft mounted on said chamber, a valve controlling said aperture and having a rod connected therewith, a guide for said valve, and means for operating said valve and including a cam for said valve, and means for producing relative motion between said valve rod and cam in a direction transverse 

